React\Promise\FunctionMapTest::shouldMapInputWhenMapperReturnsAPromise PHP Method

    public function shouldMapInputWhenMapperReturnsAPromise()
    {
        $mock = $this->createCallableMock();
        $mock->expects($this->once())->method('__invoke')->with($this->identicalTo([2, 4, 6]));
        map([1, 2, 3], $this->promiseMapper())->then($mock);
    }